Vaccine safety still concerns parents

Originally published in MedPage Today

by Kristina Fiore, MedPage Today Staff Writer

Even though 90% of parents believe vaccines protect their children against disease, many are also concerned about potential adverse effects, a new survey found.

More than half of survey respondents said they were concerned about vaccine safety profiles, particularly for newer immunizations, Gary L. Freed, MD, MPH, of the University of Michigan, and colleagues reported online in Pediatrics.

And 12% of parents said they had refused at least one vaccine for their children.

“Continued high childhood immunization rates will be at risk if current safety concerns are not addressed effectively,” the researchers wrote, noting the comparatively high refusal rate.

Parents’ unwillingness to get their children vaccinated could lead to decreased immunization among the population. This has already been seen in recent outbreaks of mumps, measles, and other vaccine-preventable diseases.

So in January 2009 as part of a larger study, researchers sent 2,521 online surveys to a nationally representative sample of parents with children under age 17. Their 62% response rate gave them a total of 1,552 participants.

The immunization most frequently refused was the HPV vaccine (by 56% of those who had refused any vaccine). That was followed by varicella, meningococcal conjugate, and finally MMR.

Prior studies had found varicella to be the most frequently refused vaccine but neither meningococcal conjugate nor HPV vaccines were included in the earlier reports because they had not been approved yet. The researchers said their finding is likely a reflection of parents’ response to newer, less trusted vaccines.

In further analyses, the researchers found that mothers were more likely to have concerns about vaccines than fathers.

For example, they were more likely to be concerned about serious adverse events (60% versus 46%, P=0.0007), to believe that some vaccines cause autism (29% versus 17%, P=0.0008), and to have ever refused a vaccine for their children (14% versus 8%, P=0.0011).

Hispanic parents were much more likely than black or white parents to report that they generally follow their doctor’s recommendations about vaccines (37% versus 23% and 22%, respectively, P=0.01).

And they were less likely to ever have refused a vaccine (5% versus 15% and 12%, respectively, for blacks and whites, P=0.04).

“This may be indicative of a lag between perception regarding vaccine safety and action,” the researchers wrote. “Another possibility is that safety concerns may currently be outweighed by societal pressure within this community to vaccinate their children.”

Parents still link vaccines and autism, the researchers said, with about one in five continuing to believe that some vaccines cause autism in otherwise healthy children.

“Although peer-reviewed original scientific research and multiple expert committees that have reviewed all available data on this issue have failed to show any association between vaccines and autism, anecdotally the concern continues to affect parents,” they wrote.

They said their findings indicate that current public health education campaigns haven’t been effective, and they called for better, targeted educational campaigns.

The study was potentially limited by selection and response bias.

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